Pirate87's Holset HX35 boosted RB25 thread- Diesel Turbo FTW!!

[HPF Chrisk]

sorry for thread jack but what intake manifold are you running 300plus?

[Cjmartz2k]

It was stock, and now it's an RB26 with an adapter plate. That is not at all related to the thread though, so if you want to start asking questions about intakes, start another thread.

[John Bristot]

*All info reflects the best of my knowledge, but please if I do err, correct me!

Ok guys, school has kept me off the forum actively for about a year now, but I've recently started trolling again only to find a lot of questions about the Holset HX35 and its application to the RB series of motors.

The Holset, as has been said many times over, is a great turbo. It flows great, and is nearly bullet proof, plus they can be had for about $250 on ebay. I am going to talk specifically about the HX35, but much of what I say also applies to the HY35 (smaller compressor) and the H1C (slightly older).

Here is a link to the Cummings page about the HX35, for basic info on the turbo:

http://www.holset.co.uk/files/...5.php

So.... It all began when my previous turbo a TO4E just wouldn't spool fast enough. I set to thinking about cheap alternatives and quickly came across the HX35. Days later I purchased one off of ebay for $250 shipped and it arrived soon after. The turbo came internally wastegated, but I run an aftermarket manifold with an external wastegate (the XO2 top mount),so I removed the actuator and welded the flap shut. The specific turbo I purchsed also came with a V-Band adapter for the down pipe which made fabbing things very easy.

Here is my setup installed, which has remained the same (and reliable) for the past 6 months.



As you can see I run a "Greddy" plenum, Q45 throttle body, Z32 maf, all tuned on a Power FC.

The HX35, simply, is a large turbo. The compressor housing is almost 11 inches across at its widest point, so to fit it mounted to the top mount manifold, I had to shave about 2 mm off the compressor housing and the valve cover. Also the compressor had to be clocked pointing straight down, where its thinnest point aligned with the valve cover.

Now that the turbo was fitted to the manifold I had to hook up the oil lines. The oil return is the same as most T3 turbos as well as the stock RB dump tube, which I reused for the return. The oil feed is slightly larger than a standard T3 so I had to get an adapter to get my lines to fit. I cannot remember the exact size, but if anyone else knows, please comment. Also, the turbo is not water cooled so anyone converting from a stocker would have to plug those lines.

The compressor intake is 4 inches in diameter so a 4" to 3" silicone coupler was used to hook everything up. The compressor outlet, being clocked to the ground required me to rig my charge pipes in the crazy snake route shown. Soon I will weld a 90º bend to the outlet to solve that annoyance.

OK, we've come along way and the turbo is finally ready to sp-sp-sp-SPOOOL!

I will soon post video to accompany this section, but for now you'll just have to take my word for it. In second gear from a 2000 rpm roll about 20 mph for me, I mash the gas. Of course there is lag, but at about 2800-3000 rpm boost starts to build until at about 3500-3800 rpm a "spike" is felt when the boost jumps from 5 psi to 10 psi, where I have my gate set, and holds to the redline- 6900 rpm.

On my last tune the car put down 300 hp somewhere near the redline at just under 12 psi.

Off to work for now, but more pics and video will follow. Hope I've helped to answer alot of questions!

How do you like the X02 manifold? Is it worth a damn?

[94ECR33]

Ok guys I like most other people on here want to upgrade my gay stock little rb25 turbo with something that im not afraid to blow up. Ive done alot of reasearch about turbos and like you guys i have found holsets. I found found a place that sells holset tubos from 300-600$ depending on the size. I have an r32 gtr fmic, greddy boost controller,turbo timer,apexi intake, and a 3.5 inch straight pipe exhaust, and a stage 5 6 puck ceramic single plate clutch, plus boost/oil pres./and exhaust temp gauges. my goal for my build is 400-450 hp. I realize that i will have toupgrade my fuel system injectors, fuel pump and get some sort of ems to suit my build. As for the turbos i have read that the hx35,hx35w,and hx40 turbos are probably my best bet to reach this goal. as for turbine sizing and compressure sizing and weather not to run internally waste gated or external im not too sure what to do. I intended to run my car as a semi race around town car mut mainly drift. im not a street racer but i dont mind pulling off from a light every now and then against somone. i dont wanna have to wait till 7 grand to get spooled right. but could somone please let me know what would be the best turbo and what i would have to do to modify it before bolting it on. like changin out parts with other turbos and which trubos they are from. anways i think u guys got a good idea of what im trying to do here so ill wait for your guys' post and see what u think. Thanks

[Cjmartz2k]

If you are talking about hp figures at the motor, even the 8 blade HX35 could easily do that. A 7 blade compressor wheel HX35 could put down 450rwhp fairly easily, and this is just a guess, but I would say 1 bar + by little more than 3000rpm in 4th gear. I would go external gate if I were you. The standard gate doesn't open until really high and on a gas motor, it could creep. You could put a knew actuator on it and port the internal gate hole, but I can't speak about that from first hand knowledge.

I'm not sure what you are saying when you mention changing parts with other turbos. You will need a new intake pipe, new intercooler pipe made, and a new downpipe if that's what you are asking.

[Sil240]

Has anyone received an email about a Cummins 5.9 BT HX35W?????Someone from china trying to sell me crap?

[streeteg]

Do you have any pics of the clearance mods you had to do of the valve cover and the turbo?

[94ECR33]

ok thanks for your input when u say u reccomend externally gated dose that get rid of my boost controller. cause i want to see how far a stock internal rb25 will take no head studs or gasket. i just wanna bolt a turbo onto my stock exhaust manifold and see what it will do for me. i just want it to last a few months untill winter and build it up eveen do a rebuild if needed. and with external gated what benifits am i getting?

[StricNyne]

i am going to be running driftingislame old setup of a hx35 with a 6boost manifold, my rb25 is bored and stroked to 2.7ish so it will be interesting to see how it plays out, its fully built so i wanna see what the max this turbo can do for me, i hear the 6boost alters the exhaust note too w000t

[mp1987]

I know it's an old topic but didn't want to make a new one!
Does anybody know which Holset HX35 do I need for RB25DET and why exactly it? I mean the whole code which comes on turbo?
I decide to put it on but now everybody asks me the whole code not only "Holset HX35" and I don't know what to say them right now.
As far as I know I want to go with 9 blade version but still they have approx 150 different versions of them.
Thanks!

[d356bud]

HX35 - no internal wastegate
HX35W - with internal wastegate

I think you mean the 7 blade version not 9 blade.

[StricNyne]

hx35 is badass i got no internal gate on mine, its spiking to 25 psi though cause of my vacuum plumbing heheeh

[mp1987]

No, I ment external gate turbo (HX35) but I need that code which consists of 1 letter and 7 numbers on it.
And I ment 9 blade turbo. HX35 doesn't come with 9 blades? I found one with 12 blades but don't know if it's HX35 (code is P3536971, 17-3536971 on the upper part and S 3458441 on the lower part. It's located on the sticker where barcode and some kind of date and time is printed)

[StricNyne]

where is part number and i can tell u mine

[Cjmartz2k]

It's stamped on the the CHRA IIRC. I want to say somewhere near the oil feed? Or was it on the exhaust housing? s***, it's been too long since I've looked at a holset. I can't wait until this summer when I can start playing with cars again

[StricNyne]

mine just got back on the road after i hit the deer, the boost is hitting hard and spiking to 25 psi, it should be 15psi, but man this thing is spooling super fast and hitting super hard but i gotta fix that spike issue ( its the plumbing on wastegate)

[mp1987]

I found out allready that this is internal gate turbo but I want external one. I will drive to other company today and look what's possible there.
Code is located here

[as240]

just unbolt the wastegate and weld the flap shut.

[l0nestar]

just unbolt the wastegate and weld the flap shut.

*ding ding ding*
We have a winner! CJ, tell him what he has won!

[Cjmartz2k]

LOL, a working turbo?


The externally gated ones are easier to fit though since they don't have all that extra casting material on the housing. i don't think it's an issue with a side/low mount though.

[Carl H]

extra casting? what extra casting material?

[opticnerv]

you might want to rotate the turbine housing so the oil feed and drain are more vertical.. looks like your oil feed is coming in from about 10 or 11 o clock

I've heard this before, but exactly why is perfectly vertical better? Does oil pressure build b/c it can't drain as fast?[/quote]

Do you have to remove the turbine wheel to rotate the center housing ?

[bmxarmy]

Nope, there is a big snap ring behind the turbine wheel. You can take it off with a big pair of channel locks. then the turbine wheel comes right off and you can rotate it anywhere you want. you will have to do this to put the outlet back were it originally was. The center part moves by loosening the 6 bolts that go in to the exhaust turbine. Mine was super tight though, I had to spray it with wd-40 and let it sit for overnight before i could get it to move. Once it moved a little it freed right up.

nolan

[opticnerv]

Thanks for the reply ! You said the turbine wheel comes right off I just want to make sure, you meant compressor housing right ? My hx35 has 4 bolts on the CHRA I will have to put some pb blaster on it I guess because it is extremely tight haha

[bmxarmy]

yes i meant compressor housing. mine was super tight also!

good luck.